1. Field of the Invention
The present invention relates to a tape loading apparatus.
2. Description of the Related Art
Recently, in tape loading mechanisms for use in magnetic recording/reproduction apparatuses in which a tape is withdrawn out of a cassette and then wrapped about a rotary head cylinder, the position in the plane, and the height and inclination of a roller post provided on a carrying member are determined by pressing the carrying member to a positioning member provided on a chassis by a reference surface of the chassis and a pressing member.
Hereinafter, a conventional tape loading apparatus will be described with reference to Japanese Laid-Open Publications Nos. 4-318361 and 4-318356.
First, a conventional structure will be described with reference to Japanese Laid-Open Publication No. 4-318361. In this publication, FIG. 5 is a partial perspective view of a loading mechanism. Reference numerals 8, 10 and 11 indicate roller posts disposed on boats 14 and 15. Reference numeral 86 and 87 indicate stoppers provided on the chassis. Reference numeral 41 indicates a feed side ring gear (a take-up side loading ring is not shown in FIG. 5, see FIG. 6). Reference numerals 53 and 55 indicate, respectively, feed side and take-up side drive shafts provided on the respective feed side and take-up side ring gears. Reference numerals 17 and 18 indicate feed side and take-up side loading guides, respectively.
The feed side and take-up side loading rings are rotated by driving means. The boats 14 and 15 which are engaged with the respective feed side and take-up side loading rings are moved along the loading guides 17 and 18 to withdraw a tape out of a cassette for the purpose of tape loading. After completion of the loading, the boats 14 and 15 are pressed to the respective stoppers 86 and 87 to position the roller posts 8, 10 and 11.
The mechanism for positioning the boats 14 and 15 when the tape loading is completed will be described with reference to FIG. 15 of Japanese Patent No. 4-318361.
FIG. 15 of the above-described publication shows a mechanism for positioning the feed side boat 14. FIGS. 15(a), 15(b), 15(c) and 15(d) are a plan view, a side elevation view, a bottom plan view and a partial cross-sectional view, respectively. For the sake of clarification, the structure of each component is simplified.
In this figure, reference numeral 86 indicates a stopper provided on a chassis 1. A cone-like pressing portion 86b is provided on an upper portion of a pin 86a. Reference numeral 14a is a V-shaped groove provided at a front end of a feed side boat 14, which has a sloped portion. The feed side boat 14 is further provided with reference surfaces at the front and rear end portions thereof. The reference surfaces of the feed side boat 14 contacts and presses the reference surface of the chassis 1 when loading is completed, thereby making it possible to perform high-precision positioning.
As shown in FIGS. 5 and 15 in the above-described publication, as the feed side ring gear 38 is rotated, the feed side boat 14 is guided along the feed side loading guide 17. After completion of loading, the feed side boat 14 is in a position such that the stopper 86 contacts and presses the V-shaped groove 14a. A driving force is constantly exerted on the feed side boat 14 by a driving means (a shaking plate 45, not shown in FIGS. 5 and 15,) via a feed side drive shaft 53 in a direction indicated by P. Therefore, the stopper 86 contacts and presses the V-shaped groove 14a, so that the V-shaped groove 14a constrains the lateral position of the feed side boat 14. Meanwhile, a force is exerted to the feed side boat 14 in a direction indicated by F, so that the reference surfaces provided on the feed side boat 14 contact and press the reference surface provided on the chassis 1, thereby constraining the back-and-forth and up-and-down position of the feed side boat 14.
Next, a method for adjusting the height of the roller post will be described with reference to Japanese Laid-Open Publication No. 4-318356, since Japanese Laid-Open Publication No. 4-318361 does not describe this method.
In this publication, FIGS. 3, 4 and 5 are partial views of a conventional boat and roller post. FIG. 4 is an enlarged sectional view of FIG. 3 viewed from arrow A. In FIG. 4, reference numeral 17 indicates a roller holding member. The roller holding member 17 holds a roller 16 through which a shaft 16 is passed. Reference numeral 18 is a pipe which is press-fit into a take-up side boat 10 and into which the tip of the shaft 16 is inserted.
FIG. 5 is a partial cross-sectional view of FIG. 4 viewed in a direction indicated by arrow B. In FIG. 5, the shaft 16 is pressed by the tip of a screw 19 engaged with a screw hole 20 provided at an end of the take-up side boat 10 toward the internal surface of the pipe 18 (reference surface), so that the shaft 16 does not spontaneously rotate. In order to fix securely the shaft 16 to the reference surface n with the tip of the screw 19, the shaft 16 is extended to some extent below a point to which the tip of the screw 19 is pressed. In this case, the pipe 18 is extended a length of h below the bottom surface of the take-up side boat 10. With this reference surface n, the inclination of the roller post with respect to the reference surface of the take-up side boat 10 is determined, so that a very high degree of dimensional precision is required for the pipe 18.
As described above, in conventional mechanisms, the height of a roller post is generally adjusted by shifting the roller post up and down in the following manner. A roller holding member 17 is rotated so that a screw 19 provided at an end of the shaft 16 integrated with the roller holding member 17 is engaged with a screw provided in the pipe 18 integrated with a take-up boat 10.
However, there are the following problems with the above-described conventional structures.
As to the positioning mechanism described in the above-described Japanese Laid-Open Publication No. 4-318361, the boats 39 and 40 are positioned with respect to the chassis 1 so that the position and inclination of the roller post are determined. For this reason, the position of the roller post with respect to each boat and the inclination of the roller post with respect to the reference surface of each post need to be secured with great precision. To this end, each boat needs to have an accurate and complicated shape and is therefore very expensive.
As to the roller post height adjusting mechanism as described in the above-described Japanese Laid-Open Publication No. 4-318356, screws need to be formed in particular components, such as the roller post holding member 17 and the pipe 18. Not only the number of parts is increased, but also the cost of each component is increased.
As described in this publication, the pipe 18 is press-fit onto the take-up side boat 10. A shaft 16 of the roller post is provided inside the pipe 18 with reference to the reference surface n so that the inclination of the roller post is determined. Thus, the inclination of the roller post is determined via a number of components. Therefore, in order to secure the inclination precision of the roller post with respect to the chassis 1, the precision of each component needs to be greatly secured, resulting in an increase in the costs of the components.
If the inclination precision and position of the roller post depart from that intended with respect to the boat, the running of a tape immediately incurs problems, which may cause damage in the tape. As described above, in the conventional loading mechanism, the number of components is large and a high degree of precision is required for each component. Thus, cost reduction of the mechanism is prevented and it is difficult to achieve quality of the tape loading apparatus.
According to one aspect of the present invention, a tape loading apparatus comprises a base, a roller post about which a tape is wrapped for tape loading, and a carrying member for carrying the roller post. The roller post includes a rotation shaft and a roller rotating about the rotation shaft, and a shaft engagement member is provided on the base for holding the roller post at a predetermined position, the shaft engagement member directly contacting and pressing one or both ends of the rotation shaft. Therefore, a simple mechanism for positioning a roller post can be made of inexpensive components, and the number of components can be reduced, thereby providing an inexpensive and highly reliable tape loading apparatus.
In one embodiment of this invention, at least one V-shaped cut is provided in the shaft engagement member, and the at least one V-shaped cut engage a respective end of the rotation shaft. Therefore, the roller post can be fixed at a predetermined position with great precision. A tape loading apparatus can be easily obtained using more simple and inexpensive components.
According to another aspect of the present invention, a tape loading apparatus comprises a roller post about which a tape is wrapped for tape loading, a rotation shaft about which the roller post is rotatably secured, the rotation shaft having a lower portion extending from a lower end of the roller post and an upper portion extending from an upper end of the roller post, a carrier member to which the lower portion of the rotation shaft is secured, a pushing mechanism for pushing on the carrier member to move the carrier member generally horizontally for tape loading, a lower member extending toward the roller post, the lower member including a lower engagement surface for securely engaging the lower portion of the rotation shaft at a lower portion fixed horizontal position as a result of force exerted by the pushing mechanism, an upper member extending toward the roller post, the upper member including an upper engagement surface for securely engaging the upper portion of the rotation shaft at an upper portion fixed horizontal position as a result of the force exerted by the pushing mechanism, and a ceiling member including a ceiling engagement surface for securely engaging a tip of the upper portion of the rotation shaft at an upper ceiling fixed vertical position as a result of the force exerted by the pushing mechanism.
In one embodiment of this invention, the lower member and the upper member each include a V-shaped cut to form the lower and upper engagement surfaces.
In one embodiment of this invention, the lower member, upper member and ceiling member are formed by a single integral structure.
In one embodiment of this invention, the lower member, upper member and ceiling member are generally parallel to one another.
Thus, the invention described herein makes possible the advantages of providing a tape loading apparatus having a loading mechanism comprising a small number of simple components. Cost can thereby be reduced while a high level of performance is achieved.
These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.